Toothbrush with motion selector button



Jam 13, mm R. L. BOYLES TOOTHBRUSH WITH MOTION SELECTOR BUTTON 2 Sheets-Sheet 1 Filed June 14 1967 HTTORNEY Jam; 13, 1970 R. L. BoY'LEs TOOTHBRUSH WITH MOTION SELECTOR BUT'I 'O'N 2 Sheets-Sheet 2 Filed June 14 1967 [IVE/ENTUR,

United States Patent 3,489,936 TOOTHBRUSH WITH MOTION SELECTOR BUTTON Robert L. Boyles, Wayland, Mass., assignor to General Electric Company, a corporation of New York Filed June 14, 1967, Ser. No. 645,959 Int. Cl. H02k 7/14 US. Cl. 310-47 9 Claims ABSTRACT OF THE DISCLOSURE An electric toothbrushing device having an electric motor, a motion converting mechanism and an operator shaft upon which a toothbrush may be mounted, the device being controlled by a switch button which may be selectively angularly positioned to cause the operator shaft to impart a back-and-forth or an up-and-down motion to a toothbrush mounted thereon.

Background of the invention My invention relates to an electric toothbrushing device and more particularly to a motion converting mechanism and selector for allowing manual selection of the mode of travel of a toothbrush which may be mounted on the device.

In recent years electrical toothbrushing devices have been widely accepted for home use. Manufacturers of these devices have met the public demand and have attempted to generate a further demand for electric toothbrushes by constructing them with various modes of toothbrush travel. Therefore, prior art devices are available which impart various motions to the toothbrush bristles such as: longitudinal reciprocation, oscillation, elliptical motion and orbital combinations of reciprocation and oscillation. Although several of these generated motions may be efficient for removing food particles from between the teeth while concomitantly being beneficial to the gingiva, a user may prefer one mode of bristle travel over another.

The disadvantage of such prior art devices in general becomes readily apparent to a prospective purchaser who prefers a specific mode of bristle travel since he is required to make his purchase on the basis of this factor alone and must disregard other factors which ordinarily may influence his judgment. Furthermore, such devices are generally used by several members of a family and there may be different preferences among its members.

Summary of the invention Accordingly, it is the primary object of my invention to provide an electric toothbrushing device which will generate both backandforth and up-and-down output motions and will allow the user to selectively determine the mode of travel of the toothbrush.

Another object of my invention is to provide a novel motion converting mechanism including a driving means and a motion selector for generating plural output motions.

A further object of my invention is to provide a unique combined ON-OFF switch and motion selector for the above device.

To accomplish these objects, in one form, an electric toothbrush device is provided which comprises a body, an electric motor disposed within the body, an operator shaft carried by the body upon which a toothbrush may be mounted, a switch for controlling the energization of the motor, and a selectively positionable motion selector for allowing a user to determine the mode of travel of the operator shaft.

Brief description of the drawings Other objects and further details of that which I believe to be novel and my invention will be clear from the following description and claims taken with the accompanying drawings wherein:

FIG. 1 is a side elevational view of the electric toothbrushing device of my invention shown partially in section;

FIG. 2 is a perspective view of the improved motion converting mechanism and switch of my invention;

FIG. 3 is a plan view of the motion converting mechanism and switch shown in the back-and-forth ON position;

FIG. 4 is a plan view similar to that of FIG. 3 showing the switch and motion selector in the OFF position;

FIG. 5 is an exploded perspective view of the motion converting mechanism and switch of my invention;

FIG. 6 is an enlarged perspective view of the motion selector disc;

FIG. 7 is an enlarged schematic view of a portion of the drive link and the motion selector shown in the backand-forth motion generating position;

FIG. 8 is an enlarged schematic view of a portion of the drive link and the motion selector shown in the OFF position; and

FIG. 9 is an enlarged schematic view of a portion of the drive link and the motion selector shown in the upand-down motion generating position.

Description of the preferred embodiment With particular reference to the drawings there is illustrated in FIG. 1 the improved electrical toothbrushing device of my invention which includes a body 10 constructed so as to be held in one hand and adapted to receive a toothbrush upon the external portion of the operator shaft 12. The body 10 comprises a generally cylindrical casing half 14 within which are disposed a usual rechargeable battery 16 and a small DC motor 18 and further includes a generally cylindrical casing half 20 within which is disposed a motion converting mechanism 22 (shown in FIGS. 2 and 5). After assembly of the operating components the casing halves 14 and 20 which are preferably formed of an electrically insulating plastic material which is relatively strong and lightweight may be secured together in a suitable manner, such as by ultrasonic welding. Energization of the motor 18 may be controlled by the external thumb operable ON-OFF switch button 24 which is simultaneously used to select the mode of travel of a mounted toothbrush, as will become apparent.

The motion converting mechanism 22 shown in perspective in FIG. 2 and exploded in FIG. 5 translates the rotational output of the motor 18 through its shaft 26, carrying pinion 28, to either longitudinally reciprocating (hereinafter referred to as back-and-forth) or rotationally oscillating (hereinafter referred to as up-anddown) motion of the operator shaft 12. The mechanism 22 includes a support bracket 30 upon which is mounted a shaft 32 carrying a face gear 34 and adapted to be driven by the pinion 28. An eccentric boss 36 formed on one face of the face gear 34 extends parallel to the axis of the shaft 32 and perpendicular to the longitudinal axis of the handle 10. Thus the rotational output of pinion 28 is translated into circular movement of the boss 36 in a plane perpendicular to the rotational plane of pinion 28.

The circular motion of the boss 36 is translated into axial movement of a drive link 38. This may be accomplished by disposing the eccentric boss 36 within a seat 40 formed on the drive link 38. A slot 42 formed in the drive link 38 is adapted to receive the shaft 32 as the drive link reciprocates. The forward portion of the drive link 38 is arcuately formed in cross-section and is received for reciprocation within a passage 44 of similar crosssection formed in the support bracket 30. An S-shaped cam slot 46 having shoulders 47 is disposed in drive link 38 at the forward portion thereof adjacent a chamber 48 formed in the support bracket 30.

The operator shaft 12 is mounted for rotation and reciprocation relative to the support bracket 30 in bearings 50 and 52 which are press-fit in seats 54 and 56 adapted to receive them. A drive pin 58 passing through the chamber 48 is secured to the operator shaft 12, being mounted through and perpendicular thereto. At one end the drive pin 58 carries a first cam follower roller 60 held thereon by a snap ring 62 and carries at its other end a second cam follower roller 64 secured in position by a snap ring 66. The first cam follower 60 is adapted to be disposed within the S-shaped cam slot 46. Thus as the pinion 28 rotates, the resulting circular motion of the eccentric boss 36 causes the drive link 38 to reciprocate and the locus of the centerline of the cam follower roller 60' moves in an S-shaped path as indicated by the arrow in FIG. 8, for imparting a combined back-and-forth and up-anddown motion to the operator shaft 12.

A motion selector disc 68, clearly seen in perspective in FIG. 6 is mounted in a seat 69 formed therefor in the support bracket 30 adjacent the chamber 48. The disc 68 is made of a suitable plastic insulating material and includes a selector ca-m groove 70 formed in one face and adapted to receive the second cam follower 64. A radially extending lug 72 projecting from the circumferential wall of the disc 68 is adapted to travel within an arcuate recessed portion 74 of the seat 69 thus limiting the degree of angular movement of the disc 68 to an arc of approximately 90 (note FIGS. 3 and 4). The wall portions 76 and 78 defining the ends of the cam groove 70 include radially outwardly extending detent protrusions 80 adapted to cooperate with indents 82 formed in the seat 69 for defining a positive stop in each of three positionsviz. back-and-forth, OFF, and up-and-down. The circumferential wall of the disc 68 opposite the radial lug 72 is formed with a diametrally enlarged portion 84 whose function will become apparent. A central boss 86 having a coupling slot 88 is formed on the face of the disc opposite the cam groove 70 for receiving a mating portion of the switch button 24.

The switch buton 24 includes an external portion 90 which may be in the form of a pointer for being directed to suitable indicia formed upon the body for designating the mode of motion of the operator shaft 12. A cylindrical shaft portion 92 of the button is passed through an opening 94 in the body 10, and the button terminates in a coupling projection 96 for engagement with the coupling slot 88 of the motion selector disc 68. The opening 94 is sealed to prevent the introduction of foreign materials into the body by means of an O-ring 100 which may be disposed within a circumferential groove 98 formed in the cylindrical shaft portion 92.

The novel ON-OFF switch of my invention is mounted upon the motion selector disc 68 and operates substantially simultaneously with the manual selection of the 'mode of travel of the operator shaft 12. The switch which includes a metallic contact disc 102 having a circular planar wall and a depending circumferential skirt 104 is mounted upon the electrically insulating plastic disc 68 and is further formed with a central aperture 106 in the planar wall adapted to receive the boss 86, a cutout 108 in the skirt 104 adapted to receive the radial lug 72 and a cutout 110 in the skirt 104 adapted to receive the diametrally enlarged portion 84. A metal contact fork 1'12 mounted upon the support bracket 30 by means of a pair of staking pins 114 is normally biased so as to be in contact with the planar wall of the contact disc 102 and may be connected to the battery 16 by a lead wire 116. A second metal contact member 118 mounted upon the support bracket 30 by means of a staking pin 119 includes a contact blade 120 which is normally radially biased against the skirt 104, a slot 122 for passage of the lead wire 116, and an ear 124 formed at its rearward end for receiving a suitable contact strip 126 which may in turn be secured to the motor 18.

To insure proper operation of the toothbrushing device, it is necessary to prevent moisture and solid particles from entering the body 10 at its forwardmost end from which the operator shaft 12 extends. For this purpose there is provided a flexible shaft seal 128 made of rubber or similar material having at one end a circumferential bead 130 adapted to be clamped between the forwardmost end of the support bracket 30 and a shoulder 132 formed at the forward end of the casing half 20 and at the other end a collar 134 for tightly surrounding the operator shaft 12.

The end 136 of the operator shaft 12 upon which toothbrushes may be mounted is generally D-shaped in cross-section thus acting as a key for receiving toothbrushes having a longitudinal passage of substantially similar cross-section. Thus, the user may manipulate the switch button 24 with his thumb and the bristles will always face in the proper direction for ease of use. The operator shaft also includes a longitudinal slot 138 formed therein and a lip 140 formed at its end for insuring firm frictional engagement of the shaft in the toothbrush for preventing the toothbrush from inadvertently falling off of the shaft.

As previously mentioned, rotation of the pinion 28 is translated to longitudinal reciprocation of the drive link 38 which in turn generates a combined back-andforth and up-and-down motion of the operator shaft 12 through cam follower 60, mounted on drive pin 58. Mo tion selection is accomplished by manually moving the external pointer of the switch button 24 in the direction of the desired motion generating position as indicated by the indicia on the body. As the button 24 and the selector disc 68 are coupled, this movement may rotate the motion selector disc 68 from its normal central OFF position 45 in either a clockwise or a counterclockwise direction, causing the selector cam groove 70 to be lo cated in one of the positions shown in FIGS. 7 and 9. The second cam follower 64 which is received in the selector cam groove 70 is constrained therein and may be moved in only one direction thus limiting the movement of cam follower 60 and the operator shaft 12. When the motion selector disc 68 is in the FIG. 7 position the selector cam groove 70 is disposed parallel to the longitudinal axis of the body and the operator shaft 12 may only move back-and-forth. With the motion selector disc 68 in the FIG. 9 position the selector cam groove 70 is disposed perpendicular to the longitudinal axis of the body and the operator shaft 12 may move only upanddown.

It has been found that the unique S-shaped cam slot 46 is a highly efficient configuration for imparting to the cam follower 60 the desired combined motion. The shoulders 47 located at the central portion of the slot are substantially perpendicular to the longitudinal axis of the drive link and thereby impart a large axial component to the cam follower 60 in the back-and-forth mode. This configuration minimizes side thrust on the drive link 38 which would tend to hang it up and may cause sluggish operation of the operator shaft 12. This slot configuration also generates the proper angular movement of the operator shaft in the up-and-down mode.

The ON-OFF switch operates substantially simultaneously with the above described motion selection. The normal central OFF position can best be seen in FIG. 8 wherein the contact blade 120 does not engage the skirt 104 of contact disc 102, but engages the diametrally enlarged portion 84 of the plastic electrical insulating motion selector disc 68. Thus the circuit through the battery 16 and the motor 18 is open. As the selector disc 68 is rotated to the FIGS. 7 or 9 positions, as described above with respect to motion selection, the skirt 104 is moved into engagement with the contact blade 120 closing the circuit and energizing the motor 18.

The simultaneous energization of the motor 18 and motion selection yields another advantage in the operation of my novel toothbrushing device. As the selector disc 68 is moved from its central position either clockwise or counterclockwise, the circuit is closed prior to locating the selector cam groove 70 in either the FIG. 7 or FIG. 9 position. This advance energization while the cam groove 70 is somewhat angularly removed from its end position causes the second cam follower 64 to be constrained in alternate paths which generate combined back-and-forth and up-and-down modes of travel of the operator shaft 12. These alternate modes may be preferred by some users.

It is understood that the present disclosure has been made only by way of example and that numerous changes in details of construction and the combination and arrangement of parts may be resorted to without departing from the true spirit and the scope of my invention as hereinafter claimed.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electrical toothbrushing device comprising:

a body;

an electrical motor disposed within said body;

an operator shaft carried by said body upon which a toothbrush may be mounted;

switch means for energizing said motor;

selectively angularly positionable motion constraining means and driving means mounted in said body and driven by said motor for driving said operator shaft; and

control means coupled with said motion constraining means for controlling said operator shaft to cause it to move back-and-forth or up-and-down with respect to said body.

2. The electrical toothbrushing device defined in claim 1 wherein said driving means comprises: a longitudinally reciprocable drive link defining a cam slot therethrough; means for translating the rotary output of said motor to a longitudinal reciprocation of said drive link; and a cam follower carried by said operator shaft for movement in said cam slot, said cam slot being formed so as to impart to said cam follower and said operator shaft the combined back-and-forth and up-and-down motion.

3. The electrical toothbrushing device defined in claim 2 wherein said cam slot is generally S-shaped.

4. The electrical toothbrushing device defined in claim 3 wherein said selectively angularly positionable motion constraining means comprises: an angularly adjustable motion selector disc coupled with said control means and defining a cam slot therein; and a second cam follower for movement in said cam slot, being carried by said operator shaft for limiting the freedom of movement of said operator shaft.

5. The electrical toothbrushing device defined in claim 2 wherein said selectively angularly positionable motion constraining means comprises: an angularly adjustable motion selector disc coupled with said control means and defining a cam slot therein; and a second cam follower for movement in said cam slot being carried by said operator shaft for limiting the freedom of movement of said operator shaft.

6. The electrical toothbrushing device defined in claim 5 wherein said switch means for energizing said motor is actuated substantially simultaneously with and by movement of said control means and comprises: an electrically conductive disc mounted on said motion selector disc, the latter being made of electrical insultating material, said conductive disc having a circumferential skirt with a cutout portion defined therein for passage of a portion of said insulating motion selector disc; a first contact member normally biased against said conductive disc and in electrical contact with said motor; and a second contact member normally biased against said skirt and in electrical contact with said said motor, for opening and closing the electrical circuit in response to the angular orientation of said conductive disc mounted on said motion selector disc, whereby the circuit is open when said second contact member is biased against said portion of said motion selector disc which passes through said cutout portion, and the circuit is closed when said second contact member is biased against said skirt.

7. The electrical toothbrushing device defined in claim 1 wherein said selectively angularly positionable motion constraining means comprises: an angularly adjustable motion selector disc coupled with said control means and defining a cam slot therein; and a second cam follower for movement in said cam slot, being carried by said operator shaft for limiting the freedom of movement of said operator shaft.

8. The electrical toothbrushing device defined in claim 7 wherein said switch means for energizing said motor is actuated substantially simultaneously with and by movement of said control means and comprises: an electrically conductive disc mounted on said motion selector disc, the latter being made of electrical insulating material, said conductive disc having a circumferential skirt with a cutout portion defined therein for passage of a portion of said insulating motion selector disc; a first contact member normally biased against said conductive disc and in electrical contact with said motor; and a second contact member normally biased against said skirt and in electrical contact with said motor, for opening and closing the electrical circuit in response to the angular orientation of said conductive disc mounted on said motion selector disc, whereby the circuit is open when said second contact member is biased against said portion of said insulating motor selector disc which passes through said cutout portion, and the circuit is closed when said second contact member is biased against said skirt.

9. The electrical toothbrushing device defined in claim 1 wherein said switch means for energizing said motor and said control means are substantially simultaneously actuated by a single switch button mounted on the exterior of said body.

References Cited UNITED STATES PATENTS 3,379,906 4/1968 Spohr 310- X 3,183,538 5/1965 Hubner. 1,464,824 8/1923 Kollock et al. 31080 MILTON O. HIRSHFIELD, Primary Examiner US. Cl. X.'R. 3l0--50, 8O 

